Blow-out preventer



vDec. 1, 1931. w. E. KING ET AL 1,334,063

BLOW-OUT PR EVENTER Fil ed Jan. 15. 1929 I VENTO z 5W wwme.

d M ATTORNEYS.

Patch ted Dec. 1,

UNITED STATES PATENT OFFICE wanrnn a. me am) IAIES 8t Anmwnonm, OI HOUSTON, Emit SAID mm Al- SIGNOB TO 8L1!) ABEBOBODIE BLOW-OUT rnnvsmm Application ma January is, me. Serial Io. exacts.

Our invention relates to an automatic operating apparatus for closing a passage at a time when there is a high pressure of fluid therein.

Our device is particularly adapted for use in combination with a blowout preventer such as is used on the casing head of deep wells, where enormous gas pressures are encountered.

It is one of the ob'ects of our invention to provide a device w ich will operate automatically when the pressure in the passage increases.

It is another object of our invention to construct a device which may be operated by fluid pressure from an external source and at the same time may be operated by the pressure encountered in the passage Still another object of our invention is to provide a ram for closing the passage, wh1ch ram has connected thereto a piston, which has a greater exposed area than the area of the ram.

A further object of our invention is to construct a device which will close without the use of external fluid pressure'but will 0 rate merely by the pressure encountered in the passage.

Other and further objects of our invention will be readily apparent to those skilled in the art to which our improvement appertains when the following description is considered in connection with the accompanying draw- I in s wherein-- ig. l is a central vertical section through a blowout preventer equippled with our 1m= provements and showing t e rams in open position. a 1

Fi 2 is a view similar to Fig. 1 but showin the rams in closed positio e present invention is shown as applied to a type of blowout preventer somewhat similar to that disclosed in the prior application for patent of James S. Abercrombie, Serial No. 278,415, filed May 7, 1928, and is also somewhat similar to the subject matter disclosed in our co-pending application No. 332,280, filed January 14, 1929.

The blowout preventer is a device adapted A that when a .the drawings, a

casing and serves as a means of closing the passage about the drill stem to prevent a flow of gas or fluid therefrom It often occurs gas pocket or formation is encountered, pressures as high as 2500 unds per square'mch force the material in t a well up through the casing. It is essential that when the gas is encountered that the well passages be instantly closed before the gas and other materials can get under headwa If the gas once starts to flow or, what is known as blow, then it is very diflicult to close the passage as sand and gravel will travel at enormous rates of speed and under very high pressure. This is one of the greatest sources of danger in bringing in a well as if a pebble or piece of gravel strikes the 11011 casing a spar may result which ignites the well and causes a tremendous loss in production and well equipment.

We have shown in the drawings a device constructed in such a manner that it will be operable by an increase in pressure occurring in the well passa e. By having reference to an or con hng member 1 is shown as interna y threadhd at 2 for attachment to the casing, casing head or an extension thereof. This flange l is adapted to be secured to the lower flange 3 of the blowout preventer body 4; any suitable means of attachment, such as bolts 5, ma be used to secure these two members toget er.

The body 4 has a central. passage 6 therethrough to accommodate the drill stem 7 or other tools which are being used in drilling a well. The body 4 is formed with a pair of 1 which are adapted to permit reciprocation of a pair of rams 7. The particular formation and construction of these rams forms no part of the present application as they are covered in the previous application of J. S. Abercrombie. These rams are connected to pistons 17 by suitable piston rods 10 which pass through a pair of stufling boxes 11 and 12, carried by a coupling member 15. This member 15 may be formed in one ormore portions and has attached thereto a cylinder 16, which is adapted to receive the piston 17 diametrically disposed cylinder openings 8 which is connected to the piston rod and causes movement of the ram 7.

We have shown inlets 19 and 19" to the cylinder 16 which permit external fluid pressure, such as steam, air or gas from an outside source to be paw into the chamber to operate the piston17 and open or close the ram 7, as desired. I

When the well starts to blow the pressure whichjmay be passed into the cylinder 16 from the inlets 19 has been found to be insufiicient to move the ram 7, as in'the event steam ressure is used the pressure the boilers is usually around three or four hundred pounds at most, so that if gas at a thousand poundsis encountered it is absolutely impossible to close the rams 7. Various ty of devices .tov assist in closing the rams 7 un er these enormous pressures have been devised, such as a. screw spindle which penetrates through the end of, the cylinder 16and carin the well bore be instantl available to move A ries a wheel or is ada ted to receive a wrench for turning it so t at the piston may be forced inwardly. However, this type has been found to be unsatisfactory as suflicient leverage can not be obtained in order to close the ram before it is seriously injured and worn away by the terrific force and the passage of mud and avel. It must be remembered that when e well starts to blow after .the rams 7 are only artiall closed that the for whichthey have been esigned.

,In'view of the foregoing it is absolutely necessary that the rams be closedinstantly and that a pressure greater than the pressure them to closed osition. ith this in view, we have devise a structure in which a bypass 20 has been made from the assage 6 to a point 21 in the head of the cyhnder 16. A

. suitable valve 22 isshown in this by-pass which may be manuall or otherwise operated. It should be note at this time that the face 18 of the piston 17 has a greater exposed area to be acted upon by the fluid pressure than has the ram 7. This is one of the feamove to the closed position, as is shown in Fig 2.

, hen a well starts to blow a very dangerous situation arises and the drillers and other emfiloyes about the well are in fear of the we catching fire, so that it is usual proinlet is formed in order that the present device may be used in connection with the arrangement as disclosed in our coending application, Serial 332,280 filed anuary 14, 1929, but does not-form any of the subject matter of the present application. The valve 22 is-preferably of a type which will (gen only when subjected to a pressure excee ng a predetermined amount, even though the handle is set for open position. Such a valve is disclosed in the application of Walter E. King, Serial No. 332,657 filed January 15, 1930. 1

While we have shown and described herein an embodiment of the present improvement which we believe to be entirely satisfactory and practical for the purpose in view, nevertheless it is to be understood that the several essential parts of the device may be constructed in various other alternative formsand it is accordingly to be understood that in the further development of the device we reserve the privilege of resorting to all such legitimate changes therein as may be fairly embodied within the spirit and scope of the invention as claimed. 7

Having described our invention, what we claim is new and Patent is: a

1. In a blowout preventer, rams to close the well bore passage, pistons connected to and operable in a separate chamber from said rams, fluid. pressure means to move said pistons, and a b point behind said pistons.

2. In a blowout preventer, rams to close the it well bore passage, pistons connected to and operable in a separate chamber from said rams, fluid pressure means to move said pistons, and a bypass from the well bore to a point behind saidpistons, whereby the ressure in the well bore on-saidrams is equa ized By the same unit-area pressure on said pisons.

3. In a blowout preventer, rams to close the well bore passage, pistons connected to and operable in a separate chamber from said rams, fluid pressure means to move said pistons, and a bypass from the well bore to a point behind said pistons whereby the res sure in the well bore on said rams is equ 'zed desire to protect by Letters i ass from the well bore to a i mamas by the same unit are: pressure on said piston, said pistons having a, greater exposed area an said rams.

In testimony whereof we have hereunto affixed our signatures, this the 10 day of J an-. nary, A. D. 1929.

JAMES S. ABERCROMBIE. WALTER E. KING. 

